Module ngx_http_gzip_module
The ngx_http_gzip_module
module is a filter that compresses responses using the “gzip” method. This often allows to reduce the size of transmitted data by half or even more.
Example Configuration
gzip on; gzip_min_length 1000; gzip_proxied expired no-cache no-store private auth; gzip_types text/plain application/xml;
The $gzip_ratio
variable can be used to log the achieved compression ratio.
Directives
syntax: | gzip |
default: | gzip off; |
context: | http , server , location , if in location |
Enables or disables gzipping of responses.
syntax: | gzip_buffers |
default: | gzip_buffers 32 4k|16 8k; |
context: | http , server , location |
Sets the number
and size
of buffers used to compress a response. By default, the buffer size is equal to one memory page. This is either 4K or 8K, depending on a platform.
Until version 0.7.28, four 4K or 8K buffers were used by default.
syntax: | gzip_comp_level |
default: | gzip_comp_level 1; |
context: | http , server , location |
Sets a gzip compression level
of a response. Acceptable values are in the 1..9 range.
syntax: | gzip_disable |
default: | — |
context: | http , server , location |
This directive appeared in version 0.6.23.
Disables gzipping of responses for requests with “User-Agent” header fields matching any of the specified regular expressions.
The special mask “msie6
” (0.7.12) corresponds to the regular expression “MSIE [4-6]\.
” but works faster. Starting from version 0.8.11, “MSIE 6.0; ... SV1
” is excluded from this mask.
syntax: | gzip_min_length |
default: | gzip_min_length 20; |
context: | http , server , location |
Sets the minimum length of a response that will be gzipped. The length is determined only from the “Content-Length” response header field.
syntax: | gzip_http_version |
default: | gzip_http_version 1.1; |
context: | http , server , location |
Sets the minimum HTTP version of a request required to compress a response.
syntax: | gzip_proxied |
default: | gzip_proxied off; |
context: | http , server , location |
Enables or disables gzipping of responses for proxied requests depending on the request and response. The fact that the response is proxied is determined based on the presence of the “Via” request header field. A directive accepts multiple parameters:
off
- disables compression for all proxied requests, ignoring other parameters;
expired
- enables compression if a response header includes the field “Expires” with a value that disables caching;
no-cache
- enables compression if a response header includes the field “Cache-Control” with the parameter “
no-cache
”; no-store
- enables compression if a response header includes the field “Cache-Control” with the parameter “
no-store
”; private
- enables compression if a response header includes the field “Cache-Control” with the parameter “
private
”; no_last_modified
- enables compression if a response header does not include the field “Last-Modified”;
no_etag
- enables compression if a response header does not include the field “ETag”;
auth
- enables compression if a request header includes the field “Authorization”;
any
- enables compression for all proxied requests.
syntax: | gzip_types |
default: | gzip_types text/html; |
context: | http , server , location |
Enables gzipping of responses for the specified MIME types in addition to “text/html
”. The special value “*
” matches any MIME type (0.8.29). Responses with the type “text/html
” are always compressed.
syntax: | gzip_vary |
default: | gzip_vary off; |
context: | http , server , location |
Enables or disables emitting the “Vary: Accept-Encoding” response header field if the directives or gzip_static are active.